Reclaiming energy from waste water in tall buildings

ABSTRACT

Electrical power is generated from falling liquids such as captured rain water, gray water and black water in tall buildings using two or more reservoirs. Fill valves for each of the reservoirs are controlled to fill the first reservoir in a raised position while emptying the second reservoir in a lowered position. When full, the first reservoir is dropped to the lowered position while imparting mechanical energy to an electrical generator and while raising the second reservoir. Next, the second reservoir is filled until full while the first reservoir is emptied, followed by dropping the second reservoir to the lowered position while imparting mechanical energy to the electrical generator and while raising the first reservoir. The cycle is repeated so that electrical generation from the falling of the liquid avoids the liquid contacting or passing through a turbine or impeller.

CROSS-REFERENCE TO RELATED APPLICATIONS Claiming Benefit Under 35 U.S.C.120

None.

FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT STATEMENT

None.

MICROFICHE APPENDIX

Not applicable.

INCORPORATION BY REFERENCE

None.

FIELD OF THE INVENTION

The invention generally relates to methods of generating electricalpower, and especially to systems which capture otherwise wasted energy.

BACKGROUND OF INVENTION

Methods and systems for generating energy from falling water are knownin several forms, the most common being hydroelectric dams which seek tocapture energy from rivers as the water they carry responds to thedownward pull of gravity.

Another method known in the art is a “pump-back” lake, which is actuallytwo lakes separated by a vertical distance. During times in whichelectricity is in higher demand or when electricity is sold for agreater value, water from the upper lake is released through ahydroelectric dam to the lower lake to generate electricity, which issold at the higher value or used to supplement the peak demand forenergy. Then, when demand is lower or energy prices are lower,electricity is purchased to pump water from the lower lake back up tothe upper lake, thereby “reloading” the upper lake to generateelectricity during the next peak demand or peak value period. The netvalue of this system is the difference between the higher value ofelectricity at the peak demand period and the lower value of electricityat the lower demand period. Most of the water, except for loss viaevaporation and absorption, is conserved throughout the process.

Several other methods and systems for generating power as water fallsthrough a building are also known or proposed. In one system, rain wateris collected from the top of tall buildings, and directed throughdownspouts through turbines which generate electricity, and finally intothe rain sewer system. Similarly, water may be collected from graysources, such as showers and clothes washers, and optionally from blacksources, such as toilets, and directed through turbines to generatepower before it is finally disposed into a sanitary sewer. Each of theseapproaches uses turbines, which essentially consist of impellers or fanblades over which the falling liquid and contaminants it carries pass,thereby converting a portion of the kinetic energy of the falling liquidand solids into rotational energy which can be directed to an electricalgenerator.

SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION

Electrical power is generated from falling liquids such as captured rainwater, gray water and black water in tall buildings using two or morereservoirs. Fill valves for each of the reservoirs are controlled tofill the first reservoir in a raised position while emptying the secondreservoir in a lowered position. When full, the first reservoir isdropped to the lowered position while imparting mechanical energy to anelectrical generator and while raising the second reservoir. Next, thesecond reservoir is filled until full while the first reservoir isemptied, followed by dropping the second reservoir to the loweredposition while imparting mechanical energy to the electrical generatorand while raising the first reservoir. The cycle is repeated so thatelectrical generation from the falling of the liquid avoids the liquidcontacting or passing through a turbine or impeller.

BRIEF DESCRIPTION OF THE DRAWINGS

The description set forth herein is illustrated by the several drawings.

FIGS. 1 a through 1 d depict four states of a system according to thepresent invention.

FIG. 2 illustrates a functional arrangement of components of agenerating system according to the invention.

FIG. 3 sets forth the four states of at least one embodiment of theinvention, including noting at which state energy is extracted from thefalling water (e.g. potential energy is converted to kinetic energy).

FIG. 4 sets forth a generalized computing platform suitable forrealization of at least one embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) OF THE INVENTION

The inventors of the present and the related invention have recognizedproblems not yet recognized by those skilled in the relevant artsregarding generation of electricity using turbines in line with flowingwater and sewage in tall buildings, down mountains, etc. Generallyspeaking, the contaminants such as sewage solids, dirt, etc., may clingto the turbine blades (e.g. impeller) and over time add mass to theturbine blades. This can eventually lower the performance of theelectrical generation to the point where maintenance is required toclean the blades, which is a costly and unclean process.

As the population increases across a mostly fixed footprint of urbanland mass, a common way to address the increasing housing needs toexpand upwards, especially In cities and land-locked areas. More andmore tall buildings will be constructed, and the need to optimize theenergy usage will be very important.

One of the systems that every building contains is a wastewater system.Energy is used to move water (and other materials) upwards in thebuilding, and the potential energy of that wastewater as it moves downthrough the building can be harnessed to create energy.

The present inventors have recognized that there are two problems withthe known solutions for generating electrical power from the potentialenergy of elevated liquids in tall buildings:

-   -   1) Clogs/Solids—in the known solutions the wastewater comes in        contact with the turbine. Depending on the amount and type of        solids in the wastewater this can lead to maintenance issues        with the turbines getting clogged and needing to be cleaned out        to resume generating power.    -   2) Frequency of waste-water flow—in many cases depending on the        occupancy of the building and the time of day the wastewater        might not be a constant flow. Known solutions only generate        power while (or immediately after) wastewater flows.        Additionally a minimum flow rate is required to engage the        turbine.

To address these problems, embodiments of the present invention use twoor more reservoirs, a feed/fill control system, and a discharge controlsystem to charge a kinetic storage device, which is then used togenerate power. This solves the problem of clogs/solids as there are nomoving pieces in-line with the wastewater to clog. This solves thefrequency issue as the invention captures small amounts of wastewateruntil the minimum amount is gathered to put the power generation inmotion. Additionally, it can continue to generate power for a shortamount of time even after the wastewater has stopped flowing.

Generally speaking, embodiments of the present invention follow aprocess as such:

-   -   1) Wastewater enters the system from above.    -   2) A fill controller sends the wastewater to one of the empty        reservoirs which is in a raised (elevated) position, while        emptying one or more of the reservoirs which is in a lower        position;    -   3) When the lower reservoir is empty and the raised reservoir is        full, through a mechanical interaction, the full reservoir is        allowed to fall or drop, while the empty reservoir(s) is/are        allowed to raise, meanwhile the falling action of the full        reservoir imparts an impulse of energy to a kinetic storage        device, while the flow of water from above may be optionally        directed around the system via a bypass;    -   4) Now, the fill controller directs the flow into the raised,        empty reservoir, while the lowered reservoir is emptied; and    -   5) Upon filling of the raised reservoir and emptying of the        lowered reservoir, they are again allowed to swap positions        (upper falling, lower raising) while making a mechanical impulse        of energy to the kinetic storage device and optionally while        diverting additional fill water through a bypass.

This process cycle is repeated for two or more reservoirs in someembodiments, thereby allowing full raised reservoirs to fall andgenerate electricity, while also raising lowered emptied reservoirs. Thekinetic storage device, such as a flywheel or raised weight, drives theinput to an electrical generator, which produces electricity on acontinuous basis due to the constant output of the kinetic storagedevice. In some embodiments, only one reservoir may be used which may belower in cost to implement, but may, depending on design details, notcapture as much energy. In such a one reservoir embodiment, thepreviously-described cycle for just the first reservoir would beimplemented, for example. The mechanism for imparting mechanical energyinto the kinetic storage device may be any of a range of mechanical,electro-mechanical, magnetic, hydraulic, and pneumatic options, such asbut not limited to a chain and sprocket drive system, a shaft drive, agear drive, a magnetic coupling, a hydraulic pump, and a pneumatic pump.

Turning to FIG. 1 a, this is illustrated in more detail in a functionalsense. It is within the skill of those in the art to adapt thefunctional diagrams in this disclosure to specific fixtures according tothe invention. An inlet (110 a) supplying liquid from above the system,such as from the roof or upper floors of a tall building or from amountain top, etc., provides falling liquid into fill valves (100),which have two or more outputs, a first output (101 a) to a firstreservoir (102 a), a second output (101 b) to a second reservoir (102b), optionally other outputs to additional reservoirs and an output (101c) to a bypass conduit.

In this state, reservoir A (102 a) is filling while in an elevatedposition, and reservoir B (102 b) is emptying (103 b) as allowed by theemptying valves (104) into an outlet conduit (110 b) which leadsdownward relative to the inlet conduit (110 a). Please note that noliquid is flowing through a turbine in this arrangement.

When reservoir A is full and reservoir B is empty, the system enters thestate shown in FIG. 1 b, in which reservoir A is allowed to fall adistance d and reservoir B is allowed to rise the same distance throughmechanical motion m₁. System controller (105) during this state closesthe valve (101 a) to fill reservoir A, and optionally opens the bypassvalve (101 c), closes the emptying valves (103 a, 103 b), and opens thebypass empty valve (103 c).

When reservoir B reaches the elevated position, and reservoir A reachesthe lower position, the system enters the state show in FIG. 1 c. Inthis state, the system controller opens reservoir A's empty valve (103a), opens the fill valve (101 b) to reservoir B, and closed the bypassvalves (101 c, 103 c). The system remains in this state until reservoirB is full, and reservoir A is empty. Please note that no liquid ispassing through a turbine in this state.

Next, with reservoir B full, the system passes through the state shownin FIG. 1 d, in which the system controller closes all valves except thebypass valves (101 c, 103 c), and during which reservoir A rises andreservoir B lowers through motion m₂, with the mechanical movement ofthe dropping of reservoir B being coupled to a mechanism to charge thekinetic storage device.

The system now returns to the first state, in which reservoir B isemptying and reservoir A and filling. This four-cycle process isrepeated indefinitely so long as fill liquid at the inlet (110 a) isavailable. During periods of slow or no fill liquid availability, thekinetic storage device serves to keep the electrical generationcontinuous.

Referring now to FIG. 2, a functional diagram of the generation chain isshown, in which the two reservoirs are shown metaphorically on a see-sawtype of arrangement to illustrate their complementary positioningrelationship. Multiple reservoirs may be utilized in other embodiments,with some lowered, some fully raised, and other in various amount oftransitioning upwards and downwards in each state of the system.

The fill valves (100) are controlled by the system control (105) toproduce mechanical energy impulses to a kinetic storage device (200),which then drives and electrical generator (201) to produce electricity(202). The kinetic storage device may be a fly wheel, a raised weight,or similar storage device.

FIG. 3 illustrates the four logical states of the system under thecontrol of the system controller (105), and the valve states of thefilling valves as described earlier for a two-reservoir embodiment.Especially noteworthing in this view of the system operation is the twoimpulses of energy (301 a, 301 b) imparted by the falling motion ofreservoir A and reservoir B, respectively. Embodiments according to thismethod avoid the use of turbines, blades and impellers, and rather usereservoirs to contact the falling liquid and the contaminants it maycontain. Thus, filling and emptying of the reservoirs is less likely tolead to clogging or clumping, and less likely to lead to systemdegradation which requires maintenance.

Although the depictions of the reservoirs in these diagrams areessentially cylindrical, this is for iconic purposes only. In specificrealizations of systems according to the invention, the reservoirs maybe of any shape which promotes thorough emptying, such as shapes withconical or funnel-shapped bottoms.

Suitable Controllers

The preceding paragraphs have set forth example logical processesaccording to the present invention. In such a system, the systemcontroller may be a hydro-mechanical state machine using timers, floats,sensors, and valves, wherein the timers and state transitions may bepowered by the fluid pressure itself. In other embodiments, acomputer-based controller may be employed, in which the logicalprocesses of the foregoing paragraphs may be realized incomputer-executable code, and in which the valves may be electricallycontrolled and the full/empty sensing may be accomplished through anumber of known devices (weight sensors, floats with senders, etc.).

In embodiments of the latter type, a suitable computing platform which,when coupled with processing hardware, realize systems according to thepresent invention, and which, when coupled with tangible, computerreadable memory devices, embody computer program products according tothe related invention.

Regarding computers for executing the logical processes set forthherein, it will be readily recognized by those skilled in the art that avariety of computers are suitable and will become suitable as memory,processing, and communications capacities of computers and portabledevices increases. In such embodiments, the operative invention includesthe combination of the programmable computing platform and the programstogether. In other embodiments, some or all of the logical processes maybe committed to dedicated or specialized electronic circuitry, such asApplication Specific Integrated Circuits or programmable logic devices.

The present invention may be realized for many different processors usedin many different computing platforms. FIG. 4 illustrates a generalizedcomputing platform (500), such as common and well-known computingplatforms such as “Personal Computers”, web servers such as an IBMiSeries™ server, and portable devices such as personal digitalassistants and smart phones, running a popular operating systems (502)such as Microsoft™ Windows™ or IBM™ AIX™, Palm OS™, Microsoft WindowsMobile™, UNIX, LINUX, Google Android™, Apple iPhone iOS™, and others,may be employed to execute one or more application programs toaccomplish the computerized methods described herein. Whereas thesecomputing platforms and operating systems are well known an openlydescribed in any number of textbooks, websites, and public “open”specifications and recommendations, diagrams and further details ofthese computing systems in general (without the customized logicalprocesses of the present invention) are readily available to thoseordinarily skilled in the art.

Many such computing platforms, but not all, allow for the addition of orinstallation of application programs (501) which provide specificlogical functionality and which allow the computing platform to bespecialized in certain manners to perform certain jobs, thus renderingthe computing platform into a specialized machine. In some “closed”architectures, this functionality is provided by the manufacturer andmay not be modifiable by the end-user.

The “hardware” portion of a computing platform typically includes one ormore processors (504) accompanied by, sometimes, specializedco-processors or accelerators, such as graphics accelerators, and bysuitable computer readable memory devices (RAM, ROM, disk drives,removable memory cards, etc.). Depending on the computing platform, oneor more network interfaces (505) may be provided, as well as specialtyinterfaces for specific applications. If the computing platform isintended to interact with human users, it is provided with one or moreuser interface devices (507), such as display(s), keyboards, pointingdevices, speakers, etc. And, each computing platform requires one ormore power supplies (battery, AC mains, solar, etc.).

CONCLUSION

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, steps, operations, elements, components, and/or groupsthereof, unless specifically stated otherwise.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiment was chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

It should also be recognized by those skilled in the art that certainembodiments utilizing a microprocessor executing a logical process mayalso be realized through customized electronic circuitry performing thesame logical process(es).

It will be readily recognized by those skilled in the art that theforegoing example embodiments do not define the extent or scope of thepresent invention, but instead are provided as illustrations of how tomake and use at least one embodiment of the invention. The followingclaims define the extent and scope of at least one invention disclosedherein.

What is claimed is:
 1. A system for generating electrical power fromfalling liquids comprising: a first reservoir having a raised positionand a lowered position, wherein movement from the raised position to thelowered position imparts mechanical energy to an electrical generator; afirst fill valve to control flow of falling liquid into the firstreservoir, the open and closed states of the first fill valve beingunder the control of a controller; a bypass conduit and a bypass valveunder the control of the controller, wherein the bypass conduit allowsthe falling liquid to pass from a height of the raised position down toa height of the lowered position; and a controller which controls statesof operation of the reservoir and the valve by: filling the firstreservoir in a raised position; responsive to the first reservoir beingfull, allowing the first reservoir to fall to the lowered position whileimparting mechanical energy to an electrical generator; responsive tothe first reservoir being emptied, raising the first reservoir to theraised position; and opening the bypass valve when the first reservoiris falling and when the first reservoir is rising, and closing thebypass valve when the first fill valve is open, thereby providing acontinuous flow of the falling liquid from the height of the raisedposition; wherein electrical generation from the falling of the liquidavoids the liquid contacting or passing through a turbine or impeller.2. The system as set forth in claim 1 further comprising: a secondreservoir disposed in the system having a raised position and a loweredposition, and in which movement from the raised position to the loweredposition imparts mechanical energy to an electrical generator; a secondfill valve to control flow of falling liquid into the second reservoir,the open and closed states of the second fill valve being under thecontrol of the controller; and wherein the controller controls at leastfour states of operation of the system comprising: while filling thefirst reservoir in a raised position, controlling emptying the secondreservoir in a lowered position; responsive to the first reservoir beingfull, and while allowing the first reservoir to fall to the loweredposition, raising the second reservoir to the raised position andopening the bypass valve; filling the second reservoir in a raisedposition while emptying the first reservoir in a lowered position andwhile closing the bypass valve; and responsive to the second reservoirbeing full, allowing the second reservoir to fall to the loweredposition while opening the bypass valve and while imparting mechanicalenergy to an electrical generator and while raising the first reservoirto the raised position.
 3. The system as set forth in claim 1 whereinthe controller opens the bypass fill valve during any state in which areservoir is falling.
 4. The system as set forth in claim 1 wherein themechanical energy is imparted to a kinetic storage device prior to beingdirected to an electrical generator.
 5. The system as set forth in claim4 wherein the kinetic storage device comprises a fly wheel.